I wasn't able to get good photos so I'll go ahead and tell you what I did. First of all, I really can afford new pencils or a pack of erasers. I have this lifelong fascination with words and crosswords are part of that. I have several Dixon Ticonderoga #1 pencils which I have had for at least 20 years. They are perfect for my crosswords, but the erasers are dried out. Last night I was working a puzzle and made a dreadful mistake. The eraser smudged my page and almost ruined it. It was too late to go out and I won't leave the house for one item anyway, so I just sat there staring at my rock hard pencil eraser, thinking.
It occurred to me that since moisture had left the eraser perhaps I could put it back. I dampened a washcloth and stuck the pencil along with the cloth into a zipper bag and zipped it up tight and left it for a few hours. When I took it out the eraser had taken on enough moisture to erase on my newsprint without ruining it. In future, I will leave them a bit longer, but it really does work. Another stingy granny test is a success.
Update: It only worked on a few of my pencils. I don't know why but, of all the same brand of pencils, only about half are erasing right. I just wanted to let you all know.
To "redeem" an old or dirty pencil tip eraser, use your hand-held pencil sharpener, place eraser tip into it, and twist away. Voila, a clean eraser again!
